150 hpdi dash gauges erratic

[Shinola2014]

While water testing today with the permanently grounded VST pump, I had some previous gauge issues re-appear.

The voltage gauge appears dead, never budged. Will need to troubleshoot this.

The tach was working at first, but by the end of the run it was hovering around 1K rpm no matter what the speed.

I'm going to check battery voltage while running to get a quick check of the charging system.

Any other troubleshooting recommendations? thanks.

 

[kevinfishman36]

Had a van that did this, after a bunch of repairs, it ended up being a faulty ground......might help?

 

[robert graham]

Remove, inspect, clean and grease all fuses and wiring connections. The moist marine environment causes corrosion on the contact surfaces....just a fine film of grease on the surfaces will help a lot!....

 

[Silvertip]

The volt meter has no relationship with the engine. It is strictly electrical system related, meaning it is merely monitoring the system. If there is any juice in the battery it will register whether the charging system is working or not. It really appears you have intermittent ground or power feeds to the instruments. Power comes from the "I" terminal on the ignition switch. Ground is ground wherever you find it but it is ultimately the NEG terminal on the battery and the smaller black wire running from the battery to the console is the BOAT ground. The ENGINE ground is the large black battery cable connected to the engine block.